Electron immunocytochemical localization of enkephalin-like material in catecholamine-containing cells of the carotid body, the adrenal medulla, and in pheochromocytomas of man and other mammals.

Enkephalin-like immunoreactivity has been localized to electron-dense secretory granules of cat and piglet carotid bodies and adrenal medullae, horse adrenal medulla, and also to human adrenal medulla and pheochromocytomas using a gold-labeled antibody technique performed at the electron microscopic level. The same granules were also demonstrated to exhibit dopamine-beta-hydroxylase-like immunoreactivity, which suggests a granular colocalization of amines and peptides in catecholamine-storing cells.